JPH059515Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a tandem pump device for a vehicle that supplies hydraulic oil to a power steering device and a hydraulic motor of an engine cooling fan, respectively.

[Prior art]

This type of tandem pump for vehicles is equipped with a hydraulic pump for the power steering system and a hydraulic pump for the cooling fan. Both hydraulic pumps are installed on a common drive shaft that rotates in conjunction with the engine, and are driven to rotate at the same time. Even in cold weather, the hydraulic oil discharged from the cooling fan hydraulic pump is supplied to the engine cooling fan hydraulic motor in the same way as in hot weather.

[Problem that the invention attempts to solve]

In such conventional technology, when it is cold, the pipe resistance increases due to the increase in the viscosity of the hydraulic oil, which increases the internal pressure of the pump and causes energy loss.In particular, hydraulic pumps for cooling fans have a large discharge volume. There is a problem in that energy loss is large because a large amount of energy is used. Additionally, if the pressure of the hydraulic pump for the power steering device increases due to the state of use of the power steering device (for example, when the power steering device is stationary), the load conditions on the entire tandem pump become extremely severe, which may cause seizure in some cases. Other problems also arise. This invention focuses on the fact that the engine cooling fan does not need to operate at low temperatures, and bypasses the hydraulic fluid discharged from the cooling fan hydraulic pump to the suction side at low temperatures to reduce pressure loss and solve the above problem. In addition to solving this problem, even if the supply of hydraulic oil from the cooling fan to the hydraulic motor is reduced or stopped in order to reduce the load on the hydraulic pump for the cooling fan at low temperatures, the power steering system will not be affected by this. A stable steering feeling is always obtained by constantly receiving a predetermined amount of hydraulic oil from the hydraulic pump for the power steering device.

[Means for solving problems]

For this purpose, the tandem pump device for a vehicle according to the present invention includes a hydraulic pump 11 for a power steering device that supplies hydraulic oil to a power steering device 30, and a hydraulic motor 14 of an engine cooling fan 15, as illustrated in the accompanying drawings. The vehicle is equipped with a cooling fan hydraulic pump 12 that supplies hydraulic oil to the cooling fan, and the rotors of both the hydraulic pumps 11 and 12 are mounted on a single drive shaft 13 that rotates in conjunction with the engine 10 and are simultaneously driven to rotate. In a tandem pump device for a cooling fan, a discharge passage 22 communicating with the hydraulic pump 12 for the cooling fan and the hydraulic motor 14 is provided, and the discharge passage is branched into a bypass passage 23 communicating with the suction passage 21 of the present invention for the cooling fan. A temperature sensor 61 that detects the temperature of the hydraulic oil supplied to the connected electromagnetic flow control valve 40 and the hydraulic motor 14 of the engine cooling fan 15.
When the temperature detected by this temperature sensor is low, all or most of the hydraulic oil passing through the discharge passage 22 is transferred to the suction passage 2 via the bypass passage 23.
1 to bypass the electromagnetic flow control valve 40.
a power steering device side hydraulic circuit comprising the power steering device 30 and the hydraulic pump 11 for the power steering device, and the hydraulic motor 1.
4. The cooling fan side hydraulic circuit consisting of the electromagnetic flow control valve 40 and the cooling fan hydraulic pump 12 is provided independently from each other.

[Effect]

When the environmental temperature of the engine 10 is low, the electromagnetic flow control valve 40 provided in the discharge passage 22 is controlled by the control device 60 to control all of the hydraulic fluid discharged from the cooling fan hydraulic pump 12 to the discharge passage 22. Alternatively, most of it is bypassed to the suction passage 21 via the bypass passage 23. When the environmental temperature of the engine 10 becomes high, the electromagnetic flow control valve 40 supplies all or most of the hydraulic fluid discharged from the cooling fan hydraulic pump 12 to the hydraulic motor 14, operates the cooling fan 15, and Cool 10.

Moreover, the hydraulic pump 11 for the power steering device has a hydraulic circuit independent from the side of the cooling fan 15, so that the hydraulic pump 11 for the power steering system can operate the hydraulic pump 11 independently of the fluctuation in the state of supply of hydraulic oil from the hydraulic pump 12 for the cooling fan to the hydraulic motor 14 of the cooling fan 15. A predetermined amount of hydraulic oil is always supplied to the power steering device 30 to operate it.

[Effect of idea]

As described above, according to the present invention, when the temperature of the hydraulic oil supplied to the hydraulic motor 14 of the engine cooling fan 15 is low, all or most of the hydraulic oil discharged from the cooling fan hydraulic pump to the discharge passage is The part is directly returned to the suction side by the electromagnetic flow control valve and does not pass through the hydraulic motor and its supply/discharge pipes, so there is almost no pressure loss despite the large discharge volume and the low temperature and high viscosity of the hydraulic oil. Therefore, almost no engine loss occurs. This reduces the load on the cooling fan hydraulic pump at low temperatures when the viscosity of the hydraulic oil is high, so even if the pressure of the power steering system hydraulic pump increases, the load conditions on the tandem pump as a whole will not become severe. Therefore, problems such as image sticking will not occur.

Moreover, even if the supply of hydraulic oil from the cooling fan to the hydraulic motor is reduced or stopped in order to reduce the load on the hydraulic pump for the cooling fan at low temperatures, the power steering system will not be affected. A predetermined amount of hydraulic oil is always supplied from the hydraulic pump, providing a stable steering feel.

〔Example〕

First, the first embodiment shown in FIGS. 1 and 2 will be explained.

In FIG. 1, a hydraulic pump 1 for a power steering device is shown.
The rotors of the cooling fan hydraulic pump 1 and the cooling fan hydraulic pump 12 are provided on a single drive shaft 13 that rotates in conjunction with the automobile engine 10, and are driven to rotate at the same time.
The power steering device hydraulic pump 11, the cooling fan hydraulic pump 12, and the drive shaft 13 constitute a tandem pump.

As shown in FIG. 1, the hydraulic pump 11 for the power steering system pumps hydraulic oil sucked from the reservoir 20 through the flow rate control valve 32, and then passes through the handle shaft 31a to the power steering system of the vehicle, which is operated by the steering handle 31. Supplied to device 30. The used hydraulic oil discharged from the power steering device 30 is returned to the reservoir 20. The hydraulic pump 11 for the power steering device is a vane pump, and its discharge amount increases according to the rotational speed of the engine 10, but the power steering device is controlled by the action of the flow control valve 32, which is activated by the pressure difference before and after the metering throttle 33. A constant flow of hydraulic oil is supplied to the device 30, and the excess flow is supplied to the power steering device hydraulic pump 11.
bypassed to the suction side. A relief valve 34 is provided on the downstream side of the metering throttle 33 to protect the power steering device hydraulic pump 11 from an abnormal increase in the discharge side hydraulic pressure.

The power steering device side hydraulic circuit consisting of the power steering device 30 and the power steering device hydraulic pump 11 described above is connected to a cooling fan consisting of a hydraulic motor 14, an electromagnetic flow control valve 40, and a cooling fan hydraulic pump 12, which will be described below. The side hydraulic circuits are provided independently and separately from each other.

The cooling fan hydraulic pump 12 is a vane pump, and as shown in FIG. 1, the hydraulic oil sucked from the reservoir 20 through the suction passage 21 is passed through the electromagnetic flow control valve 4 controlled by the control device 60 as described later.
The oil is supplied to the hydraulic motor 14 that drives the engine cooling fan 15 through a discharge passage 22 provided with a pressure of 0 to operate the engine cooling fan 15. The used hydraulic oil discharged from the hydraulic motor 14 is returned to the reservoir 20 via an oil cooler 26. The engine cooling fan 15 is
The engine 10 is cooled through a water-cooled radiator 16. The hydraulic motor 14 is provided in parallel with a hydraulic motor circuit relief valve 25 that bypasses the excess flow and limits the maximum rotational speed when the flow of the supplied hydraulic oil exceeds a predetermined amount Qo. Further, on the downstream side of the electromagnetic flow control valve 40 in the discharge passage 22, a relief valve 2 is provided that protects the cooling fan hydraulic pump 12 from an abnormal increase in the discharge side hydraulic pressure.
4 is provided.

As shown in FIG. 2, the electromagnetic flow control valve 40 includes an electromagnetic throttle valve 50 that continuously changes the opening degree of a throttle 55 that communicates with the rear half 22a of the discharge passage toward the hydraulic motor 14, and The flow rate control valve 44 operates according to the pressure difference between the two. The electromagnetic throttle valve 50 includes a valve body 51 screwed onto the housing 12a of the tandem pump, and this valve body 5.
The movable spool 52 and the solenoid 56 are supported by the valve shaft 53 and supported by the valve shaft 53, and the movable spool 52 is urged rightward together with the valve shaft 53 by a spring 54, so that the throttle 55 is normally fully opened. When the solenoid 56 is energized, the movable spool 52 moves to the left against the spring 54 according to the current value, and as a result, the tip of the valve shaft 53 approaches the throttle 55 and changes its opening degree. It is starting to decrease. The flow rate control valve 44 is mounted on the housing 1 coaxially with the valve body 51 of the electromagnetic throttle valve 50.
The main components are a valve storage hole 45 formed in 2a, and a valve spool 46 fitted into the valve spool 46 whose both sides communicate with the front and rear of the throttle 55. Valve spool 4
6 is normally biased toward the throttle 55 of the electromagnetic throttle valve 50 by a spring 4 provided between the sealing plug 48 and closes communication between the discharge passage 22, the rear half 22a of the discharge passage 22a, and the bypass passage 23. However, the hydraulic oil from the cooling fan hydraulic pump 12 flows through the discharge passage 22.
If it is supplied through the bypass passage 2, it will retreat against the spring 47 due to the pressure difference before and after the throttle 55, and the bypass passage 2
3 is branched and connected to the discharge passage 22, and a part or all of the hydraulic oil from the discharge passage 22 is returned to the suction passage 21 via the bypass passage 23. The amount of hydraulic oil that returns to the suction passage 21 from the bypass passage 23 is
The case where the throttle 55 is fully open is rare, and increases as the opening degree of the throttle 55 decreases, and when the throttle 55 is fully closed, the entire amount of hydraulic oil from the discharge passage 22 is returned to the suction passage 21. By appropriately setting the opening area of the throttle 55 and the spring force of the spring 47, the air flow from the discharge passage 22 through the bypass passage 23 to the suction passage 2
The pressure loss of the hydraulic oil returning to 1 can be made sufficiently small. The bypass passage 23 is formed in the housing 12a so as to communicate with the suction passage 21. If the bypass passage 23 is connected to the suction passage 21 at an appropriate inflow angle, suction from the reservoir 20 is drawn into the suction passage 21. The suction efficiency can be improved by giving a supercharging effect to the hydraulic oil.

As shown in FIG. 1, the electronic control device 60 is connected with an oil temperature sensor 61 that detects the temperature of the hydraulic oil in the reservoir 20 and a water temperature sensor 62 that detects the temperature of the cooling water in the radiator 16. Valve 5
0 solenoid 56 is connected. In this embodiment, the hydraulic oil temperature T detected by the oil temperature sensor 61 indicates the environmental temperature of the engine 10, and the cooling water temperature t detected by the water temperature sensor 62 indicates the load state of the engine 10. Control device 60
The solenoid flow control valve 40 is controlled by controlling the current applied to the solenoid 56 based on the hydraulic oil temperature T and the cooling water temperature t. That is, the applied current i that the control device 60 applies to the solenoid 56
When the hydraulic oil temperature T is below a predetermined temperature To (e.g. 85°C), the maximum value iA is constant regardless of the cooling water temperature t, as shown by the broken line I1 in FIG. If it exceeds , it changes depending on the cooling water temperature t as shown by the solid line I2, and when t≦t1, the maximum value iA, when t≧t2, the minimum value iB, and t1<t<t2.
In this case, the value is set to correspond to the water temperature t. The water temperatures t1 and t2 are, for example, 85°C and 95°C. Accordingly, the opening degree of the electromagnetic throttle valve 50 is determined by the broken line P1 in FIG. 4 when the hydraulic oil temperature T is below To.
As shown in , the minimum opening pA is always constant, and when the hydraulic oil temperature T exceeds To, it changes depending on the radiator water temperature t as shown by the solid line P2, and when t≦t1, the minimum opening pA, t Maximum opening when ≧t2
pB, when t1<t<t2, the opening degree corresponds to the water temperature t.

When the electromagnetic throttle valve 50 is at the minimum opening pA, most of the hydraulic oil from the cooling fan hydraulic pump 12 is returned to the suction passage 21 by the flow rate control valve 44, so that the hydraulic oil is transferred from the rear half 22a of the discharge passage to the hydraulic motor 14. The flow rate Q of the supplied hydraulic oil gradually increases with the rotational speed of the drive shaft 13 of the pump, as shown by the broken line A in FIG. 5, but the amount is small. When the electromagnetic throttle valve 50 is at the maximum opening pB, the flow control valve 4
Since the amount of hydraulic oil returned to the suction passage 21 by 4 is small, the flow rate Q supplied to the hydraulic motor 14 is
As shown by the solid line B0, the flow rate Q increases rapidly with the rotational speed of the pump's drive shaft, but when the flow rate Q reaches Qo, the motor circuit relief valve 25 operates to bypass the excess flow rate, so the flow rate Q remains constant. If the opening degree of the electromagnetic throttle valve 50 decreases below the maximum opening degree pB,
Although the rate of increase in the flow rate Q with respect to the rotational speed of the drive shaft of the pump decreases as shown by solid lines B1, B2, . . . , the maximum value Qo of the flow rate Q remains constant. The hydraulic motor 14 rotates at a rotational speed proportional to the flow rate Q of the supplied hydraulic oil, operates the cooling fan 15, and cools the radiator 16.

According to the above embodiment, the hydraulic oil temperature T of the reservoir 20 detected by the oil temperature sensor 61 is a predetermined low temperature.
If the viscosity of the hydraulic oil increases below To,
The electromagnetic throttle valve 50 is set to the minimum opening by the control device 60.
pA, and the flow rate control valve 44 bypasses most of the hydraulic oil discharged from the cooling fan hydraulic pump 12 into the discharge passage 22 through the bypass passage 23 to the suction passage 21. Therefore, since most of the hydraulic oil does not pass through the discharge pipe line provided with the rear half 22a of the discharge passage, the hydraulic motor 14, and the oil cooler 25, energy loss due to flow resistance in these parts can be prevented. In addition, this reduces the load on the cooling fan hydraulic pump 12, so even if the pressure of the power steering system hydraulic pump 11 increases, the load conditions on the entire tandem pump will not become severe, causing problems such as seizure. will no longer occur. Furthermore, when the viscosity of the hydraulic oil increases at low temperatures, the resistance in the suction passage 21 that sucks the hydraulic oil from the reservoir 20 increases, resulting in insufficient suction and cavitation. However, in this embodiment, cavitation is likely to occur. The tandem pump housing 12
Since it is returned to the suction passage 21 in a, the reservoir 2
The amount of suction from zero is reduced, and therefore cavitation due to insufficient suction can be prevented. In this state, the hydraulic motor 14 hardly operates, and therefore the cooling fan 15 also operates only slightly, but since the environmental temperature is low, the engine 10
There are no problems caused by insufficient cooling.

If the hydraulic oil temperature T becomes higher than the predetermined low temperature To,
Radiator 16 detected by water temperature sensor 62
Depending on the cooling water temperature t, all or most of the hydraulic oil from the cooling fan pump 12 is transferred to the hydraulic motor 14.
The cooling fan 15 is operated as necessary and sufficiently to cool the engine 10.

Furthermore, even if the state of supply of hydraulic oil from the cooling fan hydraulic pump 12 to the hydraulic motor 14 fluctuates due to fluctuations in the hydraulic oil temperature T, the power steering device hydraulic pump 11 can be operated from the cooling fan 15 side. Hydraulic motor 1 of cooling fan 15 with independent hydraulic circuit
Since a predetermined amount of hydraulic oil is always supplied to the power steering device 30 to operate it, the power steering device 30 is cooled, regardless of fluctuations in the supply state of hydraulic oil of the cooling fan hydraulic pump 12 to the cooling fan 4. Juan 15
It always operates reliably without being affected by the operating status of the other side.

In addition, in the above embodiment, the electromagnetic throttle valve 50
Although some passage area is left in the state of the minimum opening degree pA, it is not necessary and may be completely closed. In this case, the hydraulic motor flow rate Q in the minimum opening state becomes 0, and the cooling fan 15 stops.

Next, in the second embodiment shown in FIG. 6, in addition to all the components that operate in the same manner as in the first embodiment, there is a hydraulic pressure sensor that detects the gear generated pressure in the input pipe of the power steering device 30. 63 is connected to the control device 60. The control device 60 fully closes the electromagnetic throttle valve 50 of the electromagnetic flow control valve 40 when the gear generated pressure detected by the oil pressure sensor 63 exceeds a predetermined value, regardless of other conditions, and closes the electromagnetic throttle valve 50 of the electromagnetic flow control valve 40 to close the cooling fan hydraulic pump 12. All the hydraulic oil discharged from the cooling fan is bypassed to the suction side, and the hydraulic oil flow rate Q to the hydraulic motor 14 is set to 0, as shown by the broken line A in FIG. 7, to reduce the load on the cooling fan hydraulic pump 12. There is. When the power steering device 30 is in operation, especially when stationary, the gear generation pressure increases, so the load on the power steering device hydraulic pump 11 increases, and the load on the entire tandem pump increases. According to this embodiment, when the load on the power steering system hydraulic pump 11 increases, the load on the cooling fan hydraulic pump 12 can be reduced to reduce the peak load on the entire tandem pump. As a result, the risk of seizure due to temporary overload can be reduced to one side, and the power steering device 30 always operates reliably and is always stable without being affected by the operating state of the hydraulic motor 14. Gives steering feel.

In addition, in the second embodiment, the power steering device 3
The cooling fan 15 of the engine 10 will not operate when the 0 gear generation pressure is high, but this condition will last for a relatively short time and the engine 10 has considerable thermal inertia, so the cooling fan 15 will not operate. fan 1
Such a temporary suspension of 5 does not cause any problems.

As a modification of the second embodiment, instead of detecting the gear generated pressure using the oil pressure sensor 63, the operating state of the power steering device 30 is detected using the steering angle sensor 65, and when the steering angle exceeds a predetermined value, the cooling fan is The hydraulic oil from the hydraulic pump 12 may be bypassed to the suction side so that the characteristics shown by the broken line A in FIG. 7 can be obtained. In this modification, even if the steering angle increases, the gear generation pressure does not increase that much once the vehicle speed (and thus the engine rotation speed) reaches a certain level, so the engine 10 (or drive shaft 13)
A rotational speed sensor 65 is connected to the control device 60,
When the steering angle increases, the electromagnetic flow control valve 40 may be controlled by the control device 60 so that a characteristic as shown by the two-dot chain line C in FIG. 7 is obtained.

[Brief explanation of the drawing]

1 to 5 show a first embodiment of a vehicle tandem pump device according to the present invention, in which FIG. 1 is an overall configuration diagram, FIG. 2 is a longitudinal sectional view of an electromagnetic flow control valve, and FIG.
The figure is a characteristic diagram of changes in the applied current to the electromagnetic throttle valve.
The figure is a characteristic diagram of changes in the opening degree of the electromagnetic throttle valve, Figure 5 is a characteristic diagram of changes in the flow rate of hydraulic oil passing through the hydraulic motor, and Figure 6 is a characteristic diagram of changes in the flow rate of hydraulic fluid passing through the hydraulic motor.
7 and 7 show the second embodiment and its modification, FIG. 6 is an overall configuration diagram, and FIG. 7 is a characteristic diagram of changes in the flow rate of hydraulic oil passing through a hydraulic motor. Explanation of symbols, 10...Engine, 11...Hydraulic pump for power steering device, 12...Hydraulic pump for cooling fan, 13...Drive shaft, 14...Hydraulic motor, 15...Cooling fan, 21... Suction passage, 2
2...Discharge passage, 23...Bypass path, 30...
Power steering device, 40... Electromagnetic flow control valve, 60...
…Control device.

Claims (1)

[Scope of utility model registration request] A hydraulic pump for the power steering device supplies hydraulic oil to the power steering device, and a hydraulic pump for the cooling fan supplies hydraulic oil to the hydraulic motor of the engine cooling fan, and both hydraulic pumps are rotated in conjunction with the engine. In a tandem pump device for a vehicle, which is provided on a single drive shaft and driven to rotate at the same time, the hydraulic pump for the cooling fan is provided in a discharge passage communicating with the hydraulic motor, and the discharge passage is connected to the hydraulic pump for the cooling fan. An electromagnetic flow control valve branch-connected to a bypass passage communicating with the suction passage of the hydraulic pump, a temperature sensor for detecting the temperature of hydraulic oil supplied to the hydraulic motor of the engine cooling fan, and a temperature detected by the temperature sensor. a control device that controls the electromagnetic flow control valve to bypass all or most of the hydraulic fluid passing through the discharge passage to the suction passage via the bypass passage when the temperature is low; A power steering device side hydraulic circuit consisting of a hydraulic pump for a steering device, and a cooling fan side hydraulic circuit consisting of the hydraulic motor, an electromagnetic flow control valve, and a cooling fan hydraulic pump are provided independently from each other. A tandem pump device for vehicles.